Materials for organic electroluminescent devices

A compound of the formula (1),

• where the following applies to the symbols and indices used:
• Y is on each occurrence, identically or differently, CR or N, with the proviso that at least one group Y stands for N;
• X is on each occurrence, identically or differently, CR or N, where a maximum of two groups X stand for N;
• or two adjacent X stand for a group of the following formula (3) or (4) and the other groups X stand, identically or differently, for CR or N,
• where {circumflex over ( )} indicates the corresponding adjacent groups X in formula (1) or formula (2);
• V is on each occurrence, identically or differently, NR, C(R)2, O, S, BR, Si(R)2 or C═O;
• Z is on each occurrence, identically or differently, CR or N, where a maximum of two groups Z stand for N;
• Ar1 is an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R;
• Ar2, Ar3, Ar4 are on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R;
• Are and Ar3 and/or Ar3 and Ar4 here may also be connected to one another by a single bond or by a group selected from C(R1)2, C(R1)2—C(R1)2, NR1, O or S;
• R is selected on each occurrence, identically or differently, from the group consisting of H, D, F, Cl, Br, I, CN, NO2, N(R11)2, C(═O)Ar5, C(═O)R1, P(═O)(Ar5)2, P(Ar5)2, B(Ar5)2, Si(Ar5)3, Si(R1)2, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms, each of which may be substituted by one or more radicals R1, where one or more non-adjacent CH2 groups may be replaced by R1C═CR1, C═C, Si(R1)2, C═O, C═S, C═NR1, P(═O)(R1), SO, SO2, NR1, O, S or CONR1 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO2, an aromatic or heteroaromatic ring system selected from the group consisting of benzene, naphthalene, anthracene, benzanthracene, phenanthrene, pyrene, chrysene, perylene, fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, cis- or trans-indenocarbazole, cis- or trans-indolocarbazole, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, di benzofuran, thiophene, benzothiophene, isobenzothio-phene, di benzothiophene, pyrrole, indole, isoindole, carbazole, and a combination of these systems, which may in each case be substituted by one or more radicals R1, an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R1;
• two adjacent substituents R here may optionally form a monocyclic or polycyclic, aliphatic, aromatic or heteroaromatic ring system, which may be substituted by one or more radicals R1;
• Ar5 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which may be substituted by one or more non-aromatic radicals R1;
• two radicals Ar5 here which are bonded to the same N, P, B or Si atom may also be bridged to one another by a single bond or a bridge selected from N(R1), C(R1)2, C(R1)2—C(R1)2, O or S;
• R1 is selected on each occurrence, identically or differently, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms, or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, CN or an alkyl group having 1 to 10 C atoms, where two or more adjacent substituents R1 may form a mono- or polycyclic, aliphatic ring system with one another;
• R11 is selected on each occurrence, identically or differently, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms, or an alkyl group having 1 to 10 C atoms;
• m is 0 or 1;
• n is 0 or 1;
• p is on each occurrence, identically or differently, 0, 1, 2, 3 or 4;
• q is 0, 1 or 2;
• r is 0, 1, 2 or 3;
• with the proviso that the following compound is excluded: